1. Application Areas and Significance of Tumor Antigen-Specific T Cell Detection

(1) Research on the pharmacodynamics of cancer immunotherapy drugs (such as PD-1 antibodies, bispecific antibodies, etc.): This is used to verify whether the number and total quantity of tumor antigen-specific T cells have increased after drug treatment.

(2) New drug development and combination therapies: This is to determine whether the treatment, particularly chemotherapy, affects the total quantity of antigen-specific T cells in the body.

(3) Oncolytic virus research: This is used to verify whether the oncolytic virus, after killing cancer cells, has increased the quantity of tumor antigen-specific T cells in the body.

(4) Cancer vaccine development: This is to verify whether neoantigen vaccines, mRNA vaccines, dendritic cell (DC) vaccines, etc., induce sufficient tumor antigen-specific T cells.

(5) Development of cancer nanotherapy drugs: Many nanomedicines or immune modulators exert their effects by inducing immunogenic cell death (ICD). If ICD is induced, it should verify an increase in the total quantity of tumor antigen-specific T cells.

(6) Radiation therapy: By applying different doses of radiation to tumor tissues, the aim is to verify whether radiation therapy can induce the body to produce more tumor antigen-specific T cells.

(7) Photothermal therapy: After killing cancer cells using photosensitizers or thermosensitive agents, this is used to verify whether the antigens released by cancer cells induce the production of more tumor antigen-specific T cells.

2. Tumor Antigen-Specific T Cells are Diverse (There Could Be Tens of Thousands or Even Hundreds of Thousands)

T cells, particularly tumor antigen-specific T cells, are the main force in specifically killing cancer cells. The activation of T cells is achieved through the interaction of specific T cell receptors (TCRs) with antigens. In the thymus, V(D)J recombination can produce a large number of T cell clones, theoretically reaching up to 10¹⁵ types, each with a unique TCR. Through further screening by positive and negative selection, about 10⁶ to 10¹⁰ circulating T cell clones are ultimately formed. Therefore, the body contains millions or even tens of millions of different antigen-specific T cells, some of which are tumor antigen-specific T cells capable of recognizing tumor antigens.

Tumor antigen-specific T cells can be divided into effector tumor antigen-specific T cells (Teff) and regulatory tumor antigen-specific T cells (Treg). Effector T cells can kill cancer cells after specifically recognizing tumor antigens, while regulatory T cells cannot and may even suppress the killing of cancer cells.

3. Tumor Antigen-Specific T Cell Detection Technology – Multimer Technology (Tetramer, Pentamer)

Most T cells express a single, highly specific antigen receptor (TCR) on their surface, which binds to the MHC-antigen peptide complex and recognizes specific antigenic peptides, initiating an adaptive/specific immune response, such as T cell-mediated cellular immunity. Due to the low affinity and short half-life between TCR and the MHC-antigen peptide complex, the recombinant soluble MHC-antigen peptide complex monomer is not suitable for detecting antigen-specific T cells.

In 1996, Dr. John D. Altman from Stanford University developed MHC-antigen peptide complex tetramer technology. This technology consists of a complex of four MHC-antigen peptide monomers and a fluorescent dye, based on streptavidin with signal labeling, cross-linking four MHC molecules to form an MHC tetramer. One MHC tetramer molecule can recognize and bind to 3-4 TCRs on the same T cell surface, greatly enhancing the binding force and detection specificity between the MHC-antigen peptide complex and TCR. It also allows the successful in vitro analysis of antigen-specific T cells through flow cytometry. MHC tetramer technology has become widely used in vaccine development, cellular therapy research, and other fields, serving as the "gold standard" for quantifying T cell immune responses. Its extremely high sensitivity and antigen specificity make it suitable for related basic research and clinical applications, such as efficient sorting of specific T cells, screening of antigen epitope short peptide affinities, studying viral immune evasion mechanisms, and investigating TCR affinity on the T cell surface.

4. Enzyme-Linked Immunospot (ELISPOT) – An Effective Tool for Vaccine Immuno-Efficacy Evaluation or T Cell Detection

To detect tumor antigen-specific T cells, it is possible to custom-synthesize one or more known tumor antigen peptides, then co-incubate these peptides with antigen-specific T cells to activate them. After activation, the secretion of cytotoxic substances (such as IFN-γ) can be captured using antibodies, followed by spot color analysis. ELISPOT is suitable for analyzing specific T cells that recognize known tumor antigens. It has the following advantages:

(1) Detects antibody-secreting cells (ASC) or cytokine-secreting cells (CK) at the single-cell level, assessing the functionality of living cells.

(2) Provides a direct visual readout, where each positive cell corresponds to a spot, and the number of spots represents the number of cytokine-secreting cells. Spot size reflects the level of cytokine secretion by each cell.

(3) Cells that have been cryopreserved and thawed do not lose their immune function, which is crucial for clinical trials, allowing researchers to perform parallel analyses on patient blood samples before and after immunotherapy. If trials involve multiple clinical centers across the country or globally, patient blood samples can be cryopreserved and transported to a central laboratory for testing.

5. Limitations of Multimer and ELISPOT Technologies

(1) The number of antigen peptides that can be used is very limited, so only a few specific clones of antigen-specific T cells can be detected.

(2) The types of antigen-specific T cells that can be detected are limited, and their quantity is relatively low.

(3) The antigen peptides used may not correspond to the presence of antigen-specific T cells in the body.

(4) The detected antigen-specific T cells may not be the dominant clones or the most abundant ones.

(5) The detection of antigen-specific T cells is neither comprehensive nor accurate.

(6) The cost is high.

(7) Tetramer technology can only detect T cells that structurally recognize the corresponding peptide; confirmation of cytotoxic function requires additional marker staining.

6. Ersheng Bio's Broad-Spectrum Tumor Antigen-Specific T Cell Detection Kit

Tumor antigen-specific T cells are the main force in killing cancer cells. Due to the high heterogeneity of cancer cells and tumor antigens, there are no dominant antigens, and therefore, there are no dominant antigen-specific T cells. Traditional methods using a few peptide antigens or MHC tetramer technology to detect tumor antigen-specific T cells can only detect antigen-specific T cells for a few known specific antigens. The number and variety of detected tumor antigen-specific T cells are very limited and not comprehensive.

This product is a globally innovative product with independent intellectual property rights. It detects whole-cell antigens loaded on nanoparticles, offering comprehensive, diverse, and broad-spectrum detection of tumor antigen-specific T cells from different tissues. It is characterized by high specificity, accuracy, and comprehensive detection of tumor antigen-specific T cell types.

Ersheng Bio's detection kit can detect tumor antigen-specific T cells with both structural specificity and functional specificity, meaning that these cells can both structurally recognize tumor antigens and functionally kill cancer cells after recognizing them.

If you are interested, you can visit our company's official website or contact us directly.

Suzhou Ersheng Biopharmaceutical Co., Ltd

Phone: 0512-65197151

Email：[email protected]

Website: http://www.es-bio.com/en/

Address: Unit 610, Building B2, Biopharmaceutical Industrial Park, No. 218 Xinghu Street, Suzhou Industrial Park.